Adolescents are among the fastest growing population at risk for HIV/AIDS, and psychiatrically disturbed teens are at especially high risk. Little is known about the specific HIV/AIDS risk determinants in troubled teens, or the mechanisms by which psychopathology and substance abuse influence risk for infection in youth. The current project explores HIV/AIDS risk determinants among 360 ethnically diverse mentally ill teenagers seeking outpatient mental health services. Study aims are to (a) determine rates of risky sexual behavior and drug use among troubled youth and compare these rates to rates among teens in the general population; (b) test and compare the utility of two theoretical models in explaining AIDS-risk--the Information-Motivation-Behavior model and a Social-Personal model; and (3) test and compare the two models for theoretically important subgroups of youth (internalizing, externalizing, substance abusing). In a final integrative analysis, we will develop a profile for youth at greatest AIDS-risk based on the strongest predictors from both theoretical models. We will recruit teens from two clinics associated with the same hospital network and we will re-assess them at 6- and 9-months after the first interview. Teens and caregivers will complete a combination of interviews and questionnaires to assess AIDS information, motivation, and behavioral skills, and personal attributes, relationship concerns, and adolescent AIDS-risk behavior. Family context will be examined via two structured videotaped interaction tasks and questionnaires, and we will assess adolescent psychopathology and substance abuse via questionnaires and a structured diagnostic interview (i.e., the Diagnostic Interview Schedule for Children). Thus, we will use multiple methods to predict AIDS-risk behavior. We will use structural equation modeling to test the associations specified in the models and identify causal factors associated with disturbed teens at risk for AIDS. The long-term significance of this research is to guide the development of specially targeted AIDS prevention programs for clinically disturbed youth. AIDS prevention programs are most effective when they are tailored to specific population needs. Thus, HIV/AIDS risk determinants identified in this study can be used to develop specially targeted programs for troubled youth, and interventions that are effective in a clinical setting may be applied to teens with mental health problems in school-based settings. This study is a first step in an overall program of research designed to develop effective AIDS prevention programs for troubled adolescents.